In general, proper carpet maintenance involves regular vacuuming and periodic cleaning to remove soil by methods such as hot water extraction, shampooing, bonnet cleaning, foam cleaning, etc. Some of the soil is loosely found between carpet fibers while other soil is held upon the carpet fibers by some means such as electrostatic forces, van der Waals forces, or oil bonding. Still other soil is mechanically trapped by carpet fibers. Regular vacuuming is essential as it removes some of the loose soil that damages the fibers. Vacuuming maintains the surface appearance of a carpet and keeps the level of soil in the pile at an acceptable level. Vacuuming removes only particulate soil and some unbound or loosely bound surface dirt; therefore, other methods of cleaning are periodically required to improve the appearance of the carpet. Wet cleaning methods are better for removing oils, greases, bound dirt, and other forms of matter that cause soiling on carpet. These methods are often used by professional cleaners and trained personnel.
One type of surface maintenance machine intended for carpet cleaning is referred to as an “extractor machine.” Extractor machines are commonly used for deep carpet cleaning. In general, an extractor is a transportable self-contained device which (i) sprays cleaning liquid directly onto the carpet to create a wetted carpet portion, (ii) agitates the wetted portion with a brush, and (iii) removes some of the cleaning liquid and soil in the carpet through a vacuum system. Generally, in the extraction process a relatively large quantity of cleaning liquid is applied on the carpet. While the vacuum system recovers a portion of the applied cleaning liquid, a significant portion is retained by the carpet. As a consequence, carpet drying times are substantially longer than in other cleaning processes, such as a bonnet cleaning process.
Excessive carpet wetting may promote the growth of fungus and/or bacteria within the carpet. Additionally, carpet overwetting may cause surface stains to appear or reappear as underlying soil or stains migrate from the bottom of the carpet to its surface. Extractors are generally limited to a single operational direction as the steps of wetting, agitation, and vacuuming are sequentially performed. As a result, extractor machines may be difficult to maneuver in some environments, i.e., complex floor layouts. Another common problem with known extractors includes soiled solution suspended in the extractor head. Upon deactivation of the vacuum, the suspended soiled solution in the extractor head drops out of the head and may stain or leave an excessively wet mark. Yet another problem with extractors is that the vacuum pressures are not evenly distributed along the width of the nozzle, resulting in uneven soiled solution extraction.
Another problem associated with extractors is that the extractor pick-up nozzle must generally have a high profile in order to provide a sufficiently uniform vacuum across its width. This geometry makes the system somewhat unwieldy and difficult to use in small or tight spaces.
There is a need, therefore, for a extractor head that overcomes these problems and can efficiently and effectively remove soiled solution from carpeted areas.